appendix a - vancouver island university
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AAPPPPEENNDDIIXX BB DEPOSITIONAL ENVIRONMENTS AND FACIES
Ideal Carbonate Dominated systems TRANSITIONAL MARINE
Allochems & matrix
Tidal Flat (Super- & Intertidal)
Lagoon or Subtidal
Reef Shelf Deep Shelf Basin Floor
Reef Rock (Boundstone)
small patch reefs typical, but see below
Micrites pure; + oo-, pel- & intra micrudite
bio- (all), pel-, oo- compact mound or framework
fossil-, bio-, pelmicrites
typical; sparse bio-
Sparites sparmicrite & micsparite
bio-, oosparite
Dolomites typical in evaporite basins Chert nodular forms nodular forms nodular forms bedded form
Salt / Gypsum typical in arid climates
typical in arid climates
shallow basin
Colour light gray light & dark gray light gray light – medium gray, green, brown
dark gray - black
Sequences or most typical deposit
Supertidal: mudcracks, algal laminations; pure massive micrite;
gypsum
Intertidal: sand bars,
herringbone, flat-pebble
conglomerate, wavy / lenticular
bedding, channels, stromatolites
large variety of interbedded rock
types
micrites & biomicrites
dominant with storm wash-in of
calcarenite, oomicrite &
oosparite
whole shell coquinas
massive mounds of bound fossils
without bedding
may be biomicrite mounds or piles of fossil (spar) hash
hummocky units of bio- & pelmicrite interbedded with
micrite or
thick beds or x-beds of bio- &
oosparite or
megarippled biosparmicrite &
pelmicrite
very even, millimetre scale
laminations or
massive micrites
Typical structures
/ conditions broken, abraded fossil-sand bars
often interbedded with clastics
slumps, debris flows & turbidites
of fossil debris
often interbedded with shale / silt
Fossils stromatoporoids, algal laminates, snails, ostracods
snails, arthropods, clams, sponges
coral, bryozoa, echinoderms,
stromatoporoids, red algae
echinoderms, cephalopods, coral,
brachiopods, arthropods
rare swimming / floating types
Trace fossil community
Glossi-fungites Cruziana prominent
Trypanites Cruziana, burrowed
Zoophycus
Other Birdseye glauconite, phosphate
pyrite
Ideal Clastic Dominated Long Systems
TERRESTRIAL TRANSITIONAL MARINEMeandering River Shelf Sediment
size & texture
Alluvial Fan
Braided River Alluvial plain Channel
Delta Complex
Lagoon or Delta Bay
Beach / Barrier Island
Desert Dunes
Tidal Flat Storm Domin.
Tidal Domin.
Sub-Marine Fan
Deep Shelf, Basin Floor
Breccia v. course;immature
Conglom- erate
course – medium; immature
v. course – medium; immature
mud pebbleat base of point bar
short systemsonly
lag gravels lag gravels wacke congl. in TA
Arenite v. course;immature
v. course – medium; immature
medium –fine; some
matrix
channel mouth sand
bars
storm wash in
beds
medium – coarse; v. clean
quartz sand
fine – medium; v. well sorted
medium
Wacke sandstone
fine sands typical levee & crevasse
splay
flood wash in beds
typical fine –medium
common fine – coarseTABC
Siltstone typical at top of point bar sequence
levee & crevasse
splay
typical typical typical typicalT
common in small FUS D
Shale usually silty bay fill typical typical typical typicalTE
typical
Colour red, pink,brown
red, pink, brown, gray
red, tan, brown
red, tan, brown
grey to black; white
grey to black
white white, tan,reddish
grey to black
greenish to tan
greenish to tan
gray to dark gray
dark gray to black
Sequences massivedeposits or thick CUS
& FUS cycles
unsorted, unstratified debris
flows
laminated silts with thin
crevasse splay & levee sands; beds often dip
slightly
Bay: multiple FUS in overall CUS
Lagoon: dark,
organic-rich muds
Swash Zone: parallel
laminations gently dipping
seaward
Shoaling Wave
Zone: most kinds of
ripples & x-beds
v. large-scale x-beds 10’s–100’s
m high
calcrete /
silcrete soils
no one ideal sequence:
wavy, flaser, lenticular, bedding, abundant
small ripples, x-
beds, oscillation
ripples, mudcracks, herringbone
x-bedding
v. large-scale
planar x-beds
thinnly laminated
shales; CUS to
thin silts at top
Structures matrix
supported gravel
grain supported
gravel
climbing ripples
many variants
rippled, x-bedded channel
mouth bar cut by river;
coal cap
Lagoon: storm
wash in from
barrier; lamination or planar
x-beds
if gravel beach, gravel grain-
supported and imbricated
grains v. round and
spherical; x-bed foresets
strongly curved
may be confused with dune or braided river sand
bodies
matrix supported TA gravel;
fluid escape structures; flute, tool
marks
extreme low
energy; low oxygen
Fossils rare treesor
vertebrates
rare trees or vertebrates
plant fragments
tree frag’s, vertebrates
plant frag’s, many sparse invertebrate
types
coquina, brackish animals,
plant frag’s
Tree trunks, coquina
rare vertebrates
diverseabundant
marine vertebrates
sparse marine fossils
rare floaters / swimmers
rare floaters /
swimmers
Trace fossils
Scoyenia, roottraces
Cruziana Skolithos vertebratetracks
Glossi-fungites
Cruziana abundant
Cruziana Nerites Zoophycus
Other slumps,loading
thin coals evaporites common
evaporites (arid)
phosphate, glauconite
phosphate phosphate,pyrite
RREEFFEERREENNCCEESS Atkins, Barbara C. and Johnson, Jeffrey A. (1988): The Earth: Problems and Perspectives,
Blackwell Scientific Publications, Palo Alto.
Collison, J.D. and Thompson, D.B. (1982): Sedimentary Structures, George Allen and Unwin Ltd., London
Klein, C. and Hurlbut, C. S., Jr. (1993): Manual of Mineralogy, Revised 21st Edition, John Wiley & Sons, New York.
Leeder, M.R. (1982): Sedimentology – Process and Product, George Allen and Unwin Ltd., London
Nesse, William D. (1991): Introduction to Optical Mineralogy, Oxford University Press, New York.
Prothero, Donald R. & Schwab, Fred (1996): Sedimentary Geology – An Introduction to Sedimentary Rocks and Stratigraphy, W. H. Freeman and Company, New York.
Ren, P., Bornhold, B. & Prior, D. (1996): Seafloor Morphology and Sediment Processes, Knight Inlet, British Columbia in Sedimentary Geology 103, Elsevier Science B.V., Amsterdam
Tucker, Maurice E. (1996): Sedimentary Rocks in the Field, John Wiley & Sons, New York.
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